An easy way to remember the skeletal system is to imagine you are building a house. The skeletal system is composed of three parts: the bones, the muscles and the connective tissues. Compare the three parts of the skeletal system to construction materials. The bones make up the wooden frame of the house, or skeleton. The muscles are the sheet rock that fills out the shape of the house. The connective tissues are the nails and screws that hold it all together.
The skeleton has two parts: the axial skeleton and the appendicular skeleton. Think of the axial skeleton as the foundation of your house. The axial skeleton provides a stable core for the body and protection of essential parts. The axial skeleton is made up of your skull, spinal column--or vertebral column--and rib cage. The frame built on this foundation is like the appendicular skeleton of your body. The appendicular skeleton is composed of arms, legs, hands, feet and the pectoral and pelvic girdles. Just as the frame of a house allows it to function as a house, our appendicular skeleton allows us to function as humans--enabling us to manipulate the world around us through movement.
Movement is produced by muscles pulling on bones. While a house's frame can give you an idea of what the house may look like, the walls of a house give the house its true shape. When the walls go up on a house, you can see where the doors and windows will be, and whether there will be a front porch or an attached garage. Our muscles are just like this. Our skeleton provides a general layout for our shape--the legs are usually in the same place ... the face has the same main features. But the true form is revealed due to the different shape and size of our muscles.
The Connective Tissues
To build a sturdy house, you need the right materials to hold all the parts together. Imagine building the frame of a house without nails, screws or even glue. If you just laid the pieces of wood one on top of the other, do you think the frame would last through a storm, or even the end of the day? Chances are that the frame would collapse before long. The bones and muscles of your body are no different and are held together with various materials called connective tissues. These connective tissues include ligaments and tendons. The bones are connected to each other with ligaments. Muscles attach to bones via tendons. You can remember the difference between ligaments and tendons if you think: "Ligaments for Like to Like, Tendons for Two Types." Or think of a ligament as a nail and a tendon as a screw. Most often, you need to use a nail to attach like materials--wood to wood. You need screws to attach dissimilar materials--sheet rock to wood.
Don't Forget the Joints
Joints are an important part of the skeletal system. They provide flexibility and stability to the frame of the body. There are many types of joints in the human body just as there are many type of joints in carpentry. Each serves it own function, depending on location and materials. Divide joints into two sections to make studying them easier. First, movable joints, like hinges, allow the adjoining materials to change position for flexibility. Movable joints are mostly found in the appendicular skeleton.
Second, immovable joints, found in the axial skeleton, provide stability. Some examples of movable joints are the hinge joint at the elbow and the socket joints of the hips and shoulders. Immovable joints include the suture joints between skull bones and the cartilaginous joint of the sternum to the first rib.
- "Human Anatomy & Physiology", Elaine N. Marieb, 2007